1. Field
Embodiments of the invention relate to scanning fiber devices. In particular, embodiments of the invention relate to scanning fiber devices having at least a portion of a cantilevered free end portion of an optical fiber disposed within an actuator tube, and to methods of making and using such scanning fiber devices.
2. Background Information
FIG. 1 is a cross-sectional side view of a known scanning fiber device 100. The scanning fiber device includes a housing 102. A piezoelectric tube 104 is included in the housing and attached to the housing with an attachment collar 106. A portion of an optical fiber 108 is inserted through the piezoelectric tube. A cantilevered free end portion 110 of the optical fiber is within the housing and attached to a distal end of the piezoelectric tube. The cantilevered free end portion is flexible and may be vibrated or moved. The piezoelectric tube has electrodes 112 thereon. Wires 114 are electrically coupled with the electrodes. The electrodes may be driven to vibrate or otherwise move or scan the cantilevered free end portion of the optical fiber in one or two dimensions.
Dashed lines are used to show that the free end portion of the optical fiber may move. The movement of the optical fiber may be used to acquire an image of an area of interest. For example, the scanning fiber device may scan an illumination spot through an optional lens system and over the area in a scan pattern. Backscattered light may be captured, for example, by one or more optical fibers or photodetectors, in time series.
Notice that in the illustrated scanning fiber device the cantilevered free end portion of the optical fiber is attached to the end of the piezoelectric tube. Attaching the cantilevered free end portion to the end of the piezoelectric tube may have the potential drawback that the length of the housing may need to be longer than desired for certain implementations. In particular, the length of the housing may need to be longer than the sum of the length of the piezoelectric tube (L1) plus the length of the cantilevered free end portion (L2) of the optical fiber. This is due in part to the fact that the lengths of the piezoelectric tube and the cantilevered free end portion of the optical fiber are aligned end-to-end and are substantially non-overlapping.
Generally the housing is relatively rigid in order to provide adequate mechanical protection to the components therein. In the case of certain scanning fiber devices, it may be beneficial to have the option of shortening the length of the rigid housing at the distal end, such as, for example, to facilitate maneuverability and/or insertion of the device into tight confines.